1. Field of the Invention
The present invention relates to a radio frequency (RF) receiver, and more particularly, to a programmable variable gain amplifier (PVGA) and an RF receiver including the programmable variable gain amplifier.
2. Description of the Related Art
A variable gain amplifier is used for maintaining an expected output signal level by adjusting a gain, and is widely used in RF receivers. Recently, there has been research on variable gain amplifiers, resulting in the development of various variable gain amplifiers. Moreover, there has been recent research on precisely adjusting a gain applicable to a low-voltage operation.
A variable gain amplifier disclosed in U.S. Pat. No. 6,882,226, issued Apr. 19, 2005, controls a gain and linearity by changing the resistances of a source degeneration variable resistor and a load degeneration variable resistor by an amplification unit included in the variable gain amplifier. Accordingly, the linearity of the variable gain amplifier may be improved.
However, in the variable gain amplifier disclosed in the U.S. Pat. No. 6,882,226, a DC voltage of an output node is varied by changing the resistances. Thus, an output current is varied. Moreover, a large resistance deteriorates wide-band characteristics of an RF receiver.